Abrasive compound



Patented Apr. 5, 1927.

- UNITED STATES.

1,623,222 PATIENT OFFICE.

JOHN IBJ EDBICK WEBDEB, CLEVELAND, OHIO.

Amuis rvn' coniounn.

No Drawing.- I Application filed larch This invention relates toimprovements in abrasive compounds for use in: the grinding of valves ofgas engines, pumps and'any and all other work requiring the use ofanabrasive compound r f It has heretofore been proposedf -to-. preparesuchcompounds entirely free from oil and containing a starch binder; andto incorporate in such compounds non-drying and non-freezingingredients. Such compounds-are set forth in my Patents No. 1,353,197granted. September 21, 1920, and No.'1,534,196 granted April 21, 1925.1It has. been found, when' it was sought to'incorporate the non-freezingand non-drying ingredients such as calcium chloride in an abrasivecompound employing starch paste, that the cooked Estarchfmixture becamea syrupy, sticky mass which appreciably retarded the action of theabrasive.

The present invention relates to a method of combining such anon-freezing compound in an abrasive :havin 'a binder derived fromstarch, in which suc deleterious efl'ectsare avoided.

According to this invention a farinacco'us substance such as starch istreated with 211- kali, the alkali is neutralized, and the'massisbrought to powder form. Goldwater paste as found onthe market is such aproduct: or it may be madeup'locally for example as follows: 7

Two and one-half ounces of sulfate of ammonia' are dissolved in one andone-half pints of cold water, and filtered. This solu- --tion isthen'poured into-one and one-half -into a smooth batter.

pounds of wheat flour, and the mass beaten One and one-fourth ounces ofcaustic soda are'separately dissolved in three pints of water byboiling. This boiling solution is then poured over the batter, and themass stirred until thickened. It .is

then placed in a solution comprising two fluid ounces of hydrofluoricacid in two quarts of water, and the mixture boiled until homogeneous.The; hydrofluoric acid acts principally as a neutralizing agent. It isthen made up thick, dried and ground. The resultant product may-becalled soluble starch powder, which is hereinafter employed as thename of such a powder which may be mixed with cold water to produce apaste-like substance.

1 To prepare the abrasive compound from such a soluble starch powder, asolution of calcium choride in water is prepared in the 6,1926.seriarno. 92,943.

roper proportions to give a non-freezing lquid with aspecific gravity ofsay 1.225 to 1.250 at a temperature of 68 The, per- 7 centage of calciumchloride may be varied greatly by -the operator to adapt its strength tohis particularjneeds: for very cold climates with little or noprotection from the 0 atmosphere, a strong solution is indicated.

' Five'parts by weight of pulverized abrasive, such as silicon carbide,crushed steel,

I garnet, silica, etc., depending upon the particular class of work thecompound is to per-' form, are combined with about eight or ten parts byweight of the calcium chloride solution. already prepared. This mixtureis kept in constant agitation to prevent the solid material fromseparating.

In a separate vessel one to li ve parts of the soluble starch powder arethoroughly mixed with two to ten parts of the dry abrasive.

This dry mixture is then poured into the agitated aqueous calciumchloride-abrasive mixture above as rapidly as possible, .w'hile theagitation is still continuing. The agitation is then discontinued If itbe con- I I tinucd for. an length of time after the dry mixture of souble starch powder is incorpostringyas set forth above.

If the agitation be continued too long rated, the whole mixture becomessticky and i after the soluble starch powder is intro-- duced, a portionof the owder has passedmto solution, and causes t e stringinessmentioned: In practice it has been found that about 30 to 40 seconds issuflicient to obtain my aforesaid Patslight stirring or agitation i Themixture becomes Stiff," as the soluble starch powder goes into solution:and is in excellent form for application to the work.

It is obvious that the proportions and times above indicated may bemodified. withtion.

I claim:

-1. The method ofpreparing an abrasive compound containing solublestarch powder which comprises mixing the dry abrasive material and drycold Water paste, saturating the dry mixture with an aqueous solution,and stirring for a time sufficient to obtain a homogeneous substance butinsufiicient to permit substantial solution of the cold water paste.

2. The method of preparing an abrasive compound containing solublestarch powder which comprises mixing the ingredients with agitation fora time insuflicient to cause substantial solution of the soluble starchpowder.

3. An abrasive compound containing abrasive material and a binder formedfrom moistened soluble starch powder.

4. An abrasive compound containing abrasive material, molstened solublestarch powder, and a preservative.

out \departing fro'm the spirit of the inven 5. A homogeneous abrasivecompound containing abraslve materlal, a starch binder; a liquid actingwith said starch binder in the cold to produce and maintain a paste, andcalcium chloride.-

6. The method of preparing an abrasive compound which comprisespreparing a dry soluble starch powder, preparing a -calc1um chloridesolution containingsuspended abrasive, mixing said dry soluble starchpowder with further dry abrasive, pouring said dry mixture into saidsolution during constant stirring, and interrupting such stirring im--medlately the mass becomes homogeneous.

7. An abrasive compound containing abrasire material, a soluble starchbinder, water and a moisture-retaining substance.-

8. An abrasive compound abrasive material, a soluble starch binder,water and a non-freezingprotective substance. 1

In testimony-whereof, I .iafiix' my signature. 1

' JOHN FREDRICK WERDER.

containing

